Existing data is data that has been created using an outdated or proprietary system, is in an outdated or proprietary format, or is in need of migration to a different system or form, or a combination thereof. Many organizations continue to use systems that no longer meet the organization's needs, have become obsolete, or both. Such systems are generally referred to as legacy systems.
Existing data, or legacy data, generally results from older existing systems, but there are instances where legacy data has prevailed in a data processing environment even after the data processing systems have been modernized or migrated. Migrating legacy data is the process of moving the legacy data from an old model, schema, or structure (collectively, legacy data model) to a new model, schema, or structure (collectively, new data model). The new data model is selected to be more efficient that the legacy data model, to have better compatibility with the modernized systems, to offer improved scalability for future data growth, to provide better security and reliability, or a combination thereof.